64396921 has 2 divisors, whose sum is σ = 64396922. Its totient is φ = 64396920.

The previous prime is 64396903. The next prime is 64396963. The reversal of 64396921 is 12969346.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 34574400 + 29822521 = 5880^2 + 5461^2 .

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-64396921 is a prime.

It is not a weakly prime, because it can be changed into another prime (64396421) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (17) of ones.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 32198460 + 32198461.

It is an arithmetic number, because the mean of its divisors is an integer number (32198461).

Almost surely, 2^64396921 is an apocalyptic number.

It is an amenable number.

64396921 is a deficient number, since it is larger than the sum of its proper divisors (1).

64396921 is an equidigital number, since it uses as much as digits as its factorization.

64396921 is an odious number, because the sum of its binary digits is odd.

The product of its digits is 69984, while the sum is 40.

The square root of 64396921 is about 8024.7692178654. The cubic root of 64396921 is about 400.8252151292.

The spelling of 64396921 in words is "sixty-four million, three hundred ninety-six thousand, nine hundred twenty-one".